Blue-emitting polyfluorene (PF) polymers are being pursued as active materials in polymer light-emitting diodes,1 lasers,2-6 and sensors.7-12 To meet the requirements of practical device application, high-molecular-weight blue-emitting poly(p-phenylene) (PPP) materials including, ladder-type PPPs,13 polyfluorenes (PF),14 polyindenofluorenes (PlFs),15 and polytetrahydrophenanthrene (PTHP)16 have being widely investigated. Alkyl-substituted PFs, such as poly(9,9′-dioctylfluorene) (PFO), are among the most promising candidates for optoelectronic applications.17 Still, the inherent spectral instability of alkyl-substituted PFs (i.e. green emission upon exposure to thermal stressing) remains a significant challenge limiting full realization of their device potential.
It is now well-established that the primary source of the undesirable green emission is fluoreneone defects formed during and/or after polymer synthesis.18 Attempts to prevent defect formation have included derivitization at the 9-position with trifluoromethyl,19 silole,20 siloxane,21 silsesquioxane,22 polyphenylene,23 and dendritic benzyl-ether24 moieties. These studies clearly show that controlling the molecular structure of PF at the 9-position affords one solution toward improving material performance.
Poly(aryl ethers) (PAEs) are well known engineering thermoplastics possessing excellent thermal, chemical, radiation, and oxidative stability.25, 26 Jiang et al. prepared a series of PAE polymers bearing pendent alkyl-substituted oligofluorenes.27, 28 
Two classical methods for preparing aromatic ethers (AEs) are the copper-mediated Ullmann-ether synthesis29, 30 and electron-withdrawing-group (EWG)-facilitated nucleophilic-aromatic-substitution (SNAr) protocols.25, 31 These approaches are generally ineffective in preparing high purity materials for organic electronics (e.g., PLEDs) because elevated temperatures, copper salts, and EWGs are required for the reaction to go to completion and are difficult to remove from the product. In addition, it is difficult to prepare materials in a controlled stepwise fashion, thereby limiting control over subtle changes in molecular structure. Fine structural control is well known to dramatically impact material properties.